Natamycin (INN), also known as pimaricin and sometimes sold as Natacyn, is a naturally occurring antifungal agent produced during fermentation by the bacterium Streptomyces natalensis, commonly found in soil. Natamycin has a very low solubility in water; however, natamycin is effective at very low levels. Its minimum inhibitory concentration is less than 10 ppm for most molds. Natamycin is classified as a macrolide polyene antifungal, and as a drug, is used to treat fungal keratitis, an infection of the eye. It is especially effective against Aspergillus and Fusarium corneal infections. Other common members of the polyene macrolide antifungal family are amphotericin B, nystatin, and filipin. Natamycin is also used in the food industry as a natural preservative.
Natamycin has been used for decades in the food industry as a hurdle to fungal outgrowth in dairy products and other foods. Potential advantages for the usage of natamycin might include the replacement of traditional chemical preservatives, a neutral flavor impact, and less dependence on pH for efficacy, as is common with chemical preservatives. It can be applied in a variety of ways: as an aqueous suspension (such as mixed into a brine) sprayed on the product or into which the product is dipped, or in powdered form (along with an anticaking agent such as cellulose) sprinkled on or mixed into the product. While not currently approved for use on meats in the United States, some countries allow natamycin to be applied to the surface of dry and fermented sausages to prevent mold growth on the casing. Also, natamycin is approved for various dairy applications in the United States. More specifically, natamycin is commonly used in products such as cream cheeses, cottage cheese, sour cream, yogurt, shredded cheeses, cheese slices, and packaged salad mixes. One of the reasons for food producers to use natamycin is to replace the artificial preservative sorbic acid.
As a food additive, it has E number E235. Throughout the European Union, it is only approved as a surface preservative for certain cheese and dried sausage products. It must not be detectable 5 mm below the rind. While natamycin is approved in different applications at different levels in the world, it is approved in over 150 countries worldwide.
The European Food Safety Authority (EFSA) panel took over the responsibilities of providing scientific food safety advice to the EU from the Scientific Committee on Food in 2002. In 2009, the EFSA considered the proposed use levels of natamycin are safe if it is used for the surface treatment for these cheese and sausages types.